Global Warming Could Cause World Crop Collapse

With the U.N.-affililated Food and Agriculture Organization (FAO) already warning of declining grain harvests due to extreme weather, a U.S. study released last week suggests that global warming could cause world agricultural systems to face possible collapse by 2080, with countries in the south being the hardest hit.

India, Pakistan, most of Africa and most of Latin America would be the areas most affected, according to the Washington-based Center for Global Development and the Peterson Institute for International Economics. India, which is fast becoming the world's most populous nation, could stand to see its agricultural yield to fall 29 to 38 percent. William Cline, the study's author and a well-known economist, notes that global yields for major crops have actually slowed down. "There's already a sign that there is fatigue in the Green Revolution," he said, noting that the average annual growth in yields during the 1960s and 1970s was 2.6 percent per year — yet by the 1980s and 1990s it had slowed to 1.8 percent.

"The problem is that you need the technical change to keep up with demand for food," emphasizes Cline. "I estimate that the global demand for food after you take into account higher population, as well as higher incomes, would about triple from now to late in the century."

While some analysts believe that excess carbon dioxide in the atmosphere in fact will benefit crops, citing laboratory studies that show a yield increase of 30 percent, Cline counters that farm field studies have demonstrated that benefits from so-called "carbon fertilization" is closer to 15 percent and eventually leveling out.

Conversely, food production in northern countries, especially in industrialized nations, could increase due to the effects of global warming increasing the length of the growing season. Cline cautions however that it will not meet world demand for food.

Already, there is an increasing competition between human and wild/domesticated animals for food supplies — worldwide meat production is increasing and most of it depends on grain — ultimately bringing into question the future sustainability of such a trend.

Using modelled projections on temperature and rainfall, the study's results could also be further aggravated by unpredictable factors such as crop pests, severe droughts and water shortages.

"Governments and millions of poor people in developing countries have limited ability to cope with such changes," said Nancy Birdsall, president of the Centre for Global Development. "At least a billion people live in the poorest countries that are likely to be worst hit by this slow-moving crisis. This will be a serious problem for us all."::Planet Ark & ::InterPress Service